Comparative Assessment of Different Transition Criteria for Crossflow Instabilities

Kurzfassung

The crossflow (CF) velocity profile of a three-dimensional boundary layer can become unstable and trigger laminar-turbulent transition [1]. The effect can be simulated by Reynolds-averaged Navier-Stokes (RANS) computations using a local correlation-based transition model, for example the γ-Reθt model [2], together with an appropriate model extension that captures the CF-dominated transition [3]. For a high Reynolds number, the current extensions in the DLR TAU code result in transition locations too upstream with respect to the experimental reference locations, and therefore they have to be modified in order to extend their application range. The two existing CF extensions, based on the C1 criterion and a helicity criterion [3], respectively, are investigated to identify the potential of improving them by the recalibration of specific model parameters.